October 1, 2011
PLANTS ARE VITAL to life on this earth. We depend upon plants for many of our basic needs: the air we breathe, the food we eat, as a source of fuel, clean water, fiber, clothing, shelter, and as the basis for a growing number of lifesaving medications.
Plants are a key element of biodiversity, an important constituent of habitat infrastructure for many ecosystems and the key to the earth's environmental equilibrium and stability.
Despite the essentialness of plants to our existence, today almost one quarter of all plant species face the threat of extinction. Four plant species risk extinction every day. Without human intervention, many plant species will disappear in our lifetime. Endangered species are threatened with extinction either because too few individuals survive to reproduce or because those individuals are threatened.
As defined by the California Native Plant Society, plants presumed to be extinct are those that have been actively sought in likely areas, but not found for a number of years, or those whose habitat is known to have been destroyed or significantly modified. Rare species are those that occur in limited numbers in the wild and/or have a limited range of distribution. For example, federal wildlife officials recommended endangered species protection in 2009 for a San Francisco manzanita plant, Arctostaphylos hookeri franciscana — which had been thought to be extinct for more than 60 years — after a single shrub was discovered in the Presidio. Without intervention, the plant would have been doomed — it was growing in the path of new roadway construction.
The disappearance of so many plant species in the midst of ever-increasing population growth sets up one of the greatest challenges we face as a species. The U.S. Fish and Wildlife Service estimates that losing one plant species can trigger the loss of up to 30 other insect, plant and higher animal species.
In a survey report released in September, the U.S. Fish and Wildlife Service listed 645 plant species as endangered and 150 as threatened, or a total of 795 at-risk species in this country.
For California, an area with a wealth of distinct habitats, varied soils and microclimates and one of the most diverse floras on earth, the report lists 179 plant species as endangered or threatened. Included in the list of 15 endangered or threatened species in Marin are Baker's and yellow larkspur, Presidio manzanita, mariposa lily, and Tiburon paintbrush and jewelflower.
In an attempt to halt the loss of biodiversity, several forward-thinking groups around the world have begun to save seeds in seed banks.
The Millennium Seed Bank (MSB), a project of the Royal Botanic Gardens begun in 1974 in Kew, England, in conjunction with 50 countries
including the United States, has banked close to 300 million seeds from 24,000 plant species or 10 percent of the world's wild plant species. Its goal is to save 25 percent of the world's species by 2020. When preserved in state-of-the-art facilities around the world, these seeds should be capable of germination after periods of as long as 200 years.
Another major seed repository, Svalbard Global Seed Vault, a part of the
Doomsday Vault, is set on an archipelago in the Arctic Ocean halfway between Norway and the North Pole. This underground vault is meant to secure the planet's food supply, as it is less vulnerable to the threats of war, climate change or a natural catastrophe.
If you are interested in getting involved in seed conservation nearer to home, the University of California Botanical Garden in Berkeley is an excellent resource for information about conservation programs to protect endangered and common California plants.
Holly Forbes, garden curator, was awarded the Center for Plant Conservation's 2011 Star Award for her dedication to the preservation of endangered species. She oversees the collection and research dealing with seeds and endangered plants, and manages the conservation programs
at the Botanical Garden. She will be speaking on Thursday, October 6 on Seed Saving at the Marin Art and Garden's Livermore Room at 7 p.m.
If you would like to help in the conservation effort, the SPROUT Seed Library in Bolinas and the Seed Bank Store in Petaluma are good places to start. The SPROUT Seed Library provides seeds and plants to gardeners who grow out the plants from seed. They then return seeds from their
plants to the Library for others to grow. The Seed Bank Store in Petaluma is a local source of more than 1,200 varieties of heirloom seeds.
In the future we may need a much greater range of species, particularly if climate change alters growing seasons, or the world's population continues to increase and we run out of prime agricultural land. We can't afford to let plants, and the potential they hold, die out. Our very existence depends on it.